Petroleum tar



C. D. READ Sept. 6, 1932.

PETROLEUM TAR Filed June 2.5, 1927 lPatented Sept. v6, 1932 UNITEDSTATES l PATENT OFFICE C'ARLYILIIE D. BEAD, 0F HAQIHIIIYIIOIYID,INDIANA, ASSIGOR T0 STANDARD OIL COMPANY,

OF WRITING, INDIANA, A CORPORATION OIE' INDANA PETROLEUM creialApplication- Bled June 23,

This invention relates to petroleum tare and particularly pressure tarswhich result from a cracking process operated at high temperatures and asubstantial pressure.

The invention will readily be understood from the followingX-descriptiondn connection with the accompanying drawing which showsdiagrammatically an apparatus whereby the pressure 'tar may beproducedand treated according to the invention.

Referring to the drawing, 10 is a heating coil; 11 isa retort orconversion chamber; 12 is a reflux condenser for overhead from saidchamber; 13 is a flash-drum for tar from chamber 11; 14 is a filter forlthe residue Jfrom said Hash-drum; 15 is a fractionating condenser 'forthe overhead from the Hash-drum; 16 is a receiver `for the heavcondensate therefrom; 17 is a liming tan in which a portion of .saidcondensate'is adapted to be charged with lime; and 18'is a feed-pipeleading to the heating coil 10.

A ump'19 is provided for supplying charging stock under pressure totheheating coil 10. The outlet 20 of the heating coil 10 leads into theconversion chamber 11,' which is maintained at a desired crackingtemperature byburners 21. The conversion chamber 11 lis suitablyprovided with a scraper l for the purpose of removing coke formingmaterial from the walls thereof and' causing it to fall to the bottom ofthe chamber. From the upper end of the conversion `chamber 11 a vaporpipe 22 leads tothe redu); condenser 12, which may be provided'with-suitable fractionating and condensing devices (not shown) A vaporpipe 42 leads from the (top of the fractionating condenser 12 to asuitable condenser (not shown).' Reux condensate may be returned fromvcondenser 12, through line 23 byfpump23a to the heating coil 10. Fromthe lower end of the conversionchamber 11 a pipe 24 leads to thedash-drum 13, said Apipe 24-beirg provided with a valve 25. From thetopioifcI the drum 13 a pipe 23.1eads tothe lower part cf thefractionating condenser 15 which is provided withsuitablejfractionating, and condensing devices (not shown). From thebase of this condenser a'. pipe 27 leads into 1927. Serial N0. 201,004.

the receiver 16 and from the to thereof a pipe 493 leads to a suitablecony enser (not shown). From the underside of the drum 13 apipe 28 leadsinto the iilter 14. suitable pump, for example, a hot oil .-pump', '29is. provided inthe line. 28 for orcingithe pressure tar residuum intothe "iilte'r 14.

The filtered pressure tar residuum passes fromthe filter 14 by pipe 30.

The heavy pressure tar distillate receiver to the upper portion of'saidtank. Said pipe 35 is provided with a circulating pump 36- and a hopper37 by meansof which lime and other substances, such `as water, may beadded to the oil circulated by pump 36 and may thereb be disseminatedthroughout the 011 in tan 17 Fromthe bottom ofl tank 17, a

pipe 38 leads into the feed-line 18.l `.A pump 39 is provided inthe line38. f

Thel operation lis as follows:

\ Heavy pressure-tar distillatey is pumped from receiver 16 through line32 by pump 33 'into tank 17 until it is nearly full. The distillatein`tl1en circulated through pipe 35 by pump 36 from the bottom tothe topof the tank 17 Hydrated, powdered lime is fed into the circulating Voilby the hopper 37 and is carried by the circulating oil into tank 1 7 Acertain amount of water is thenl supplied l A pump 33 is provided byhopper 37, saidwater assisting niaterial-` ly in theproduction oi asatisiactor suspension or slurry of lime in the oil. ile the suspensionis being produced and, also,

preierably,whileit is being used, the oil in 'the tank 17 is agitated byair introduced by the perforated pipe 34.- It is'preferred'to produce inthis manner a slurry of lime containing approximately 1.5 pounds perallon. The amount or water used-may suita ly be about 0.8% byl volume bithe oil. Thisv method'of mixing lime with' the -oil is .not

part of the present invention since it iedef tofa'suitable condenser(not shown). f, Ordinarily, onlyea small part of theheavy oil heavier tan asoline, such as gas oil, '1o

eavy'parain distillate, or mixtures of two or more thereof. Oil slurryis fed to the charging stock'through line 3,8'by pump 39 in quantitysuicient to provide a suitable lime content in the oil-passing throughthe heating coil 1'0 and the conversion chamber 11. A suitablequantityof lime is approximately 0.5 pounds per barrel of .chargingstock. i f V The temperature and pressure conditions in the heating coiland the conversion chamber. 11- mayV vary within wide limits. Forexample, the outlet tem erature of the 850 and thetpressure may suitablybe about 325X to 400 pounds per .square inch. The chamberll may beheated by the burners 21 to maintain a suitable craclnngtemperaturetherein.

`a0 The fractionating/*condenser 12 is con'-l of chamber 11 and isaccompanied by more` *or less coke whichis roducedfin the oil, as:A wellas lime and calcium sulfide which are, disseminated .in solid form 'inthe coke and in the tar. The withdrawal is effected continuously, orperiodically, through the valve '25 and pipe 24 and the .tar is flashedin the drum13 which is maintained substantially 4g;v at atmosphericpressure. The .overhead gasses by a pipe 26 to theA fractionating con-4enser 15 in which the heavyv pressure tar distillate is condensed, thecondensate passing by pipe 27 tothe receiver 16.. The light --eratedlime and carbonaceous matter.

pressure tar distillate vapors pass by pipe 43 preesure tar distillateis used in the tank 17 for the production of theoil slurry; the re umainder is withdrawn bypipe'l to beuse'd in producing blendedchargestock.

, The pressure tar residue is pumped in alhot condition through .pipe'28 'by pump 29 into the filter 14. Ordinarily, it is preferred to use apressure filter but any other suitable filter may bev used. Amongothers; filters of the Sweetland and Kelly type are suitable; The filtersurfaces vmay suitably be gon'stituted by CI woven metal, 'such asfabrics wo'en from pump 19 ma be any suitable hydrocarbon arariin lighten s, 'pressure tar distillate,

'heatin coll 10 may suitably e about 820 to r steel, copper, brass, orother suitable metallic If desired, the lime may be introduced into thepressure tar otherwise *thanl above described. For example, a slurry oflime in oil,

preferably reduced pressure tar, may be introduced into the reducedpressure tar in pipe 28 byv a pipe 41 immediately before said tar entersthe filter 14. j

The lime exerts two effects which aid materially in the satisfactoryproduction of ltered pressure tar residuum. On the one hand, the limeneutralizes acidic substances which would otherwise be present in thepressure tar, thereby preventing corrosion ofthe filter and partlcularlythe metal iiltersurfaces. Onthe other hand, the lime and cari bonaceousmatter togetherv form readilylterable agglomerates, and also the limeitself constitutes, together with the coke, a suitable filter mediumwhich materially aids in-preventing passage ofother solid' materialwhile permitting the liquid constituents to pass.

During the process the lime is converted, more or less completely tocalcium sulfide and probably other calcium compounds arer formed. Theterm lime in the' appended claims is therefore intended to beunderstood' generically to include calcium oxygen compounds, calciumsuldes and other calciuin compounds.

Although the present invention has been I described in connection withthe details of a specific embodiment thereof, it is notV intended thatsuch details should be regarded as limitations u on the scope of theinvention, exceptfr in so -ar as included` in the accompanying claims.

1. The method of'producing pressure tar free from coke and otherobjectionable solid materials which'comprises adding lime to ahydrocarbon oil and subjecting such oil to cracking'to produce vaporousproducts and unvaporized pressure tar containing lime and carbonaceousmatter inreadily filterable agglomerates, separately withdrawing thesaid ressure tar and forcing the same through a ter medium, therebyremovlng the aggloming lime with a'hydrocarbon oil .and Sub-A jectingsuch oil to cracking under pressure, separately withdrawing vaporizedand unvaporized products, reducing the pressure upon said liquidproducts to effect vaporization of the lighter constituents thereof,thereby producing a reduced pressure tar containing said lime andcarbonaceous matter in readily lterable agglomerates, and passing thesaid pressure tar While in heated condition through a lter medium toseparate therefrom lime, coke and other solid materials, therebyremoving the agglomerated lime and carbonaceous matter.

CARLYLE D. READ.

